Electric-arc lamp



s. P. JOHNSON.

ELEGTRIG ARC LAMP.

No. 521,798. Patented June 26, 1894.

INVEN! OR BY @fl'ez W.

A TTORNEY UNITED STATES PATENT OFFICE.

S. P. JOHNSON, OF SOHENEOTADY, NElV YORK.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 521,798, dated June 26, 1894.

Application filed December 20, 1892. Serial Ila-455,803. (No model.)

To aZZ whom it may concern.-

Be it known that I, S. P. JOHNSON, a subject of the King of Sweden and Norway, residing at Schenectady, in the county of Schenectady and State of New York, have invented a new and useful Arc Lamp, of which the following is a specification.

My invention relates to improvements in arc lamps intended for use on constant current circuits, and the objects of myimprovements are to provide a lamp with as simple a mechanism as possible While at the same time it is efficient. I attain these objects by the mechanism illustrated in the accompanying drawings, in which Figure 1 is a front view of the mechanism. Fig. 2, is a top View of the clutch shown in Fig. 5. Fig. 3. is a side view of the mechanism. Fig. 4 is a view of the mechanism looking at Fig. 3 from the top, the upper half of the mechanism not being shown for clearness.

Referring to Figs. 1 and 3 it will be seen that my lamp mechanism consists chiefly in the pair of shunt spools (13) which operate upon cores located therein as shown, said cores being pivoted on screws (9, 9) in a carrier frame (12) in such a manner that the cores can enter the shunt spools (13, 13). The carrier 12 has integrally part of it an arm to which are attached the adjusting spring (8) and also a link (14). This link(l4t) connects the above arm to the left hand end of the lever (15), Figs. 1 and 3, which carries the clutch (19) Figs. 2 and 3, at a position a little right to the center thereof, Fig. 3. The right hand end of this lever (15) is pivoted to the wrought iron armature (16) of the series spool (11), said series spool having a Wrought iron part (17) into which the armature (16) is pivoted, the other end of the wrought iron part (17) is carried upward and across to the core of series spool (11) thereby forming a closed path for the lines of force, after the armature (16) has been moved up in a horizontal position by the series spool (11).

The operation of my lamp will now be intelligible. The current from line first enters the series spool (11) energizing it to attract its armature (16). This raises the right hand end of the lever (15) and carries with it the link (18) which in turn transmits this upward motion to the clutch (19), the clutch having a slot (21) to receive the link (18) and a hole (22) nicely fitting the rod (4). The moment the right hand end of the clutch is raised it binds on the rod (4.) raising it, this therefore raises the positive carbon carried by said rod (4) and the arc is formed between the positive and negative carbons. The moment this occurs a certain amount of the current passes through the shunt spools (13) as they are connected in parallel with the carbons. If now the arc should become too long on account of their burning away, the shunt spools (13) suck their cores in a certain distance proportionately to the amount of the current flow- 1 ing in them, which is governed by the length of the arc. The longer the arc the more current would flow through the shunt spools, producing a longer pull on their cores against the spring (8) thereby carrying with them the carrier frame (12), the link (14.) and the left hand end of the lever (15) which in turn would cause a downward movement of the link (18) and the clutch (19). If now the current through the shunt spools becomes so great as to allow the clutch (19) to touch the lower part (20) of the mechanism frame (5), the rod (4t) is released from the clutch and drops through it a short distance at which time the carbons come closer together and the resistance of the arc becomes lessened. The current flowing through the shunt spools is reduced and the cores, the carrier frame, the link (14:) and the left hand of the lever (15) carrying with it the link (18), clutch (19) and rod (4) carrying with it the positive carbon, all raise until the arc becomes normal, or in other Words until the pull of the shunt spools (13) is exactly balanced by the spring (8), the tension on the spring (8) governing the length of the arc, or which is the same thing, the voltage at which the lamp burns. There is a certain distance of motion of the mechanism which brings the carbons closer together without releasing the clutch thereby keeping the are at a normal resistance or length. One great advantage in this construction will be seen in the fact that as the series spool (11) is stationary, it does not act difierentially with the shunt spools. Any slight changes in the number of amperes flowing through the series spool does not interfere with the proper feeding of the lamp.

Having described my invention so that any end of the second lever 15 actuated by the seone skilled in the art to which it pertains ries spool 11 in combination with a clutch 19 10 may make and use the same, what I claim as linked to the lever 15 near its center as demy invention, and wish to secure by Letters scribed.

5 Patent, is S. P. JOHNSON.

In an arc lamp an arm or lever 12 actuated Witnesses: by the shunt spools 13, a second lever 15 BOYD THISTLE,

linked to said arm 12 at one end, the other JAMES WV. VEEDER. 

